This is a fan art of Vladimir Malakhovskiy - https://www.artstation.com/artwork/Jlaqz0

this character is a part of a bigger project - https://www.artstation.com/artwork/1nwDgG
The first step was to roughly model the main shapes, then I used masking and extract for the metal plates.
Made some mistakes while I was modeling the knight - at first I tried to make it very polished, which didn't work and later I had to add bumps and irregularities to the metal.